Motor protector for ventilating fans



Jan. 7, 1941. R. A. lLG ETAL MOTOR PROTECTOR FOR VENTILATNG FANS Filed Aug. s, 1939 Patented Jan. 7, 1941 PATENT OFFICE .l

y 2,228,116 Y A l MOTOR PROTECTOR FOR yENTILATiNG FANsQ Robert A. Ilg and Paul F. Iig, Chicago, Ill. i Application August 3, 1939, Serial No. 288,0844

3 Claims.

The article of this invention is designed to exhaust inflammable gases and fumes from a spray booth, paint room, or like enclosure. into the outer atmosphere. The devices used for this purpose are usually electrically driven fans mounted in an opening in a wall of the room, and the laws of many States prohibit locating the fan motor in a situation where those inflammable fumes flow over the motor, for the reason that in doing so some of the fumes rather easily find their way inside the motor, become heated and ignited and explode, wrecking the motor and sometimes setting re to the buil-ding. Consequently, heretofore the motor has been located at some distance f to one Side of the fan on the outer side of the room and belted to the fan shaft.

Our present invention retains the direct driven fan wherein the latter is mounted on or co-axial with the rotating armature shaft of the motor, locating the fan in an opening in the wall and in such a position as to suck or draw off vthe gases from the spray booth or room, and locating the motor on the outer side; and, to prevent the outiiowing gases from bathing the motor, inserts, between the fan and the motor, a guard or shield of such a size and shape as to deflect and divert the outilowing gases entirely around and out of contact with the motor. In the preferred form of the invention, hereinafter described and shown in the accompanying drawings, the guard or shield is a section of a sphere of a generally umbrella shape having a central opening for the passage of the fan shaft and attached at its outer peripheral edge to the radial arms of the motor supporting saddle or frame.

A practical and approved embodiment of the invention is illustrated in the accompanying drawing, in Which- Fig. l is an elevation of the device viewed from the right of Fig. 2.

Fig. 2 is a vertical section taken on the line 2 2 of Fig. 1.

Fig. 3 is a detail perspective View, illustrating the manner of attaching the motor shield to the supporting arms of the motor.

In the drawing, I designates a. Vertical Wall of a spray booth, paint room, or the like, which is to be ventilated to iid it of the inilammable gases and fumes that are created by the Work done therein. In this wall is a circular opening II, in which is fitted an angle ring I2 attached to the wall I0 by screw bolts I3.

Id designates as an entirety a 'conventional electric motor, such as is commonly used to energize propeller fans, said motor being mounted on the wall I0 by means of a ring or saddle I5 encircling the motor frame, and radial arms I6 attached to and connecting the rings I and I2. The motor shaft I1, as is common, is extended beyond one side of the motor to form a fan shaft I1', on which is keyed the fan I8. This fan I8 may be a common and well known propeller fan, in this case reversed so as to ydirect the gases and fumes toward, instead of from, the motor I4; it being understood that the motor is mounted on the outer side of the Wall I0.

Where a fan of this type is employed in the wall of a kitchen to expel cooking odors, it does not injure the motor by directing the expelled air against the mot-or; in fact, it may have a benelicial effect on the motor by keeping down the temperature of the latter. But where it is used to expel inammable or explosive gases or fumes, it may, as hereinbefore stated, seriously damage the motor and/or create a serious re hazard. 'Ihe main object of our present improvement is to permit this type of fan to be used in a spray booth, paint room, or the like, without creating this possible damage or fire hazard.

In accordance `with our invention, we interpose between the fan and the motor a guard or shield which prevents the gases or fumes from coming in contact with the motor by deflecting and diverting them around the motor. In its preferred form this shield is a concave-convex, generally umbrella-shaped member I9 disposed co-axially with the fan and motor and formed with a central hole -20 just large enough to rpermit the passage of the fanshaft I1. To support the shield rigidly in the position shown, substantially radial lugs 2| are cut and bent from the peripheral portion of the shield and these lugs are apertured at 22 (Fig. 3) to register with apertures 23 in the motor supporting arms vI 6, and the lugs and arms are united by rivets or bolts indicated at 24. The cutting and bending inwardly of the lugs 2I forms in the periphery of the shield notches '25 which straddle the arms I6, as clearly shown in Fig. 1. This provides a very simple and strong support for the shield, maintaining the latter at all times co-axial with the fan and water.

The shield I9 is disposed with its convex side toward the fan, so that the gases and fumes expelled by the latter are deiiected and diverted outside the motor, as shown by the arrows in Fig. 2, so that the motor is Wholly protected from any contact with such gases and fumes, and its safety and normal operation are thus assured.

An additional motor protector which is preferably employed, consists of a hollow shield 26 *of suitable size and shape to enclose that portion of the motor frame lying rearwardly of the shield I9 and attached by any suitable means to the 'motor ring or saddle I5. This auxiliary shield 26 will serve to receive any ne particles of paint carried Fby the fan blast that would otherwise be .deposited on the motor itself, where a high temperature motor might ignite such deposits or where the latter are of such nature that ordinary motor temperatures might ignite them.

We claim:

1. In 'a Ventilating device for spray booths, paint rooms, and the like, the combination with an electric motor, of means for mounting the same on the outer side of a Wall of the room to be ventilated comprising a ring mounted in `an opening in said Wall, a ring embracing said motor, and radial arms connecting said rings; a fan mounted on the motor shaft within said first named ring and operating to exhaust fumes from said room and expel them to the outside atmosphere; and a concavo-convex motor shield of greater diameter than the motor and co-axial with the fan and motor located between the fan and motor with its convex side next to the fan, said motor shield being attached at its periphery to, and supported by, said arms.

2. A specific embodiment of the subject-matter `dened in Iclaim l, wherein the motor shield attaching means comprises lugs cut and bent from the periphery of the motor shield and attached to the arms.

3. A specic embodiment o'f the subject-matter dened in claim l, wherein the motor 'shield attaching means comprises radial lugs cut and bent inwardly from the periphery of the motor shield and attached to the arms, and the notches formed by the cutting and bending of said lugs straddle the arms.

ROBERT A. ILG. PAUL F. ILG. 

